It depends on it's color and texture. P star 875 is very clear and that makes it more valuable than amber that are opaque. The more uncommon colors such as red, blue, and green amber are more valuable, but the lemon-brown color of p star 875 is less so.

Most amber colored rings are valued from anywhere between $35 to $75 depending on the size, setting, and quality of the stone. To find out an approximate value of your ring, it is always best to have a reputable jewelry take a look at it. Even if it is an heirloom, you may find it is not worth much.

The amber is only a semi precious, maybe only $5-$20 bucks for the stone, odds are that that marking means that the metal is a silver "special sauce", and has minimal value, I would expect even a hundred bucks for it.